EP1790450A1 - Device for vacuum forming a plastic supporting plate having undercuts - Google Patents

Abstract

Apparatus for vacuum forming a plastic carrier plate (12) with undercut projections (18) comprises a molding plug with projecting pieces (29) mounted loosely in guides (28) with a retaining mechanism (31) for moving them between a working position and a demolding position.

Description

The invention relates to a device for vacuum forming a carrier plate of a plastic film with protruding from a support plane, at least one undercut having elevation according to the preamble of claim 1.

From the EP 0 581 092 B1 a device for vacuum forming a pin plate made of a plastic film has become known, comprising a base plate on which a plurality of mold pins are provided for the surveys to be formed a support plate made of plastic film. In each case a flexible elastic disc is attached to a main body of the trunnion, which is held down by a fastening element to the main body of the trunnion. The bending elastic disc has projections which protrude radially outwardly beyond the lateral surface of the base body. When vacuum forming a carrier plate of a plastic film surveys with undercuts are formed by the projections of the flexurally elastic disc. When removing or removing the carrier plate after its production, the projections of the flexurally elastic disc can be deflected upward, so that a simple lifting is sufficient for the projections to be released from the undercut.

From the DE 38 14 999 A1 Furthermore, a device for deep drawing of stackable pallets shows that have a bottom, the edge of which is formed with undercut beads. For the preparation of these pallets, a device is provided, in which on a base body protruding protruding ledges are provided for the formation of these undercut beads. These beads are pivotally mounted by a fixed axis of rotation to the body and include a tension spring, which returns the strip after working out the pallet in a working position.

From the FR 2 187 512 Furthermore, an arrangement for producing a carrier plate made of a plastic film, which includes recesses with undercuts. For this purpose, frustoconical basic body are provided, which have projections which protrude radially in a working position relative to the conical surface of the frusto-conical base body to the outside and are brought into a demolding flush with the conical surface in abutment. These projections are pivotally supported by a fixed axis of rotation and are actuated via a screw spindle.

From the DE 33 03 913 A1 Furthermore, an arrangement for forming plastic parts with a divided undercut forming tool is known, the tool sections along a parting line abut each other, which exits above and below the undercuts. These tool sections are locked together during forming in a position forming the undercut.

After reshaping of the workpiece, unlocking of the workpiece parts is required before it is possible to remove the deformed workpiece.

The invention has for its object to provide a device for producing a carrier plate of a plastic film with protruding from a support plane, at least one undercut having surveys, which has a structurally simple structure, allows easy removal and vacuum forming an exact positioning of the projections to the body ensures.

This object is achieved by a device according to the features of claim 1 allows. Further advantageous embodiments and modifications of the invention are specified in the further claims.

The inventive design of mold projections, which are loosely inserted in each case a guide of a base body and remain positioned both in a working position during vacuum forming a support plate of a plastic film and the demolding of the finished support plate by a hold-down device in the respective leadership, has the advantage that even with larger, acting on the mold protrusions forces during vacuum forming a working position can be safely taken and then easy removal of the support plate is made possible. In addition, the loose inserted into the guide form projections have the advantage that a simple and quick installation is given. In addition, a basic body can be equipped in a simple manner with differently formed in the form of geometry projections. At the same time, this device according to the invention is suitable both for use in the discontinuous production and in the continuous production, in which the base plate is applied to a rotating drum.

The hold-down device preferably has an end plate which partially overlaps the form projections and is provided on a shaft extending into the base body. This is a structurally simple Design provided by which all provided on the main body shape projections can be kept evenly and simultaneously, both in a working position and in a removal position during demolding of the support plate. The hold-down device is preferably at least slightly movable in Entformungsrichtung, so that the mold protrusions are free to move from the undercuts in the direction of a longitudinal central axis of the trunnion pivotable or displaceable in this direction or learn a superposition of the directions of movement.

It is preferably provided that the hold-down device comprises a shank carrying the end plate, which passes completely through the main body and the base plate and engages at the free end of a hold-down element. As a result, a compact construction can be provided. At the same time it can be made possible that a vacuum can be sucked through a bore in the main body and the base plate, through which the shaft is passed, in order to enable the uniform and dimensionally accurate production of the elevations.

The hold-down element is formed according to a preferred embodiment as a spring element, preferably as a compression spring. As a result, an independent resetting of the mold protrusions from a demoulding position into a working position can take place. At the same time the mold pins are positioned in the working position, so that a uniform quality of the surveys is ensured.

The hold-down device preferably limits the guidance of each shaped body to the longitudinal center axis with its shaft, which is arranged in a longitudinal central axis of the base body and passes through it. As a result, the shaft has a double function. On the one hand, the hold-down function is fulfilled via the front plate and, on the other hand, a movement of the mold projections which dips into the guide in the direction of the longitudinal center axis is limited.

To accommodate the mold projection, the guide in the body preferably a bearing surface, which of a freestanding nose of Mold protrusion is seen from the longitudinal center axis inclined to the base. A support surface of the mold projection is supported in a working position on the support surface. As a result, a stable arrangement and secure contact of the mold projections on the base body in the working position can be given. At the same time, this bearing surface forms a stop for the radially outwardly directed pivotal movement of the molding projections.

The guidance of the mold projections in the base body advantageously comprise in the removal direction aligned and mutually parallel guide surfaces, within which the mold projection is guided displaceably and / or pivotally. As a result, at least a slight pivoting movement and / or displacement movement of the mold projections during removal of the carrier plate is achieved as soon as the lateral surface of the elevations is guided past the mold projections.

For facilitated pivotal arrangement of loosely arranged in the guides form projections is provided according to an advantageous embodiment of the invention, pointing to the inner end of the guide, which is formed between the support portion and the shank of the hold-down device, a rounded transition region is provided on the mold protrusions, the a support surface connects with an opposite contact surface of the molding projection. As a result, unwinding can be promoted by an at least small pivoting angle.

Between the support surface of the guide and the shank of the hold-down device, a wedge-shaped movement space for the mold projections is preferably formed, whose contact surface and support surface are arranged at an angle which is smaller than the angle of the wedge-shaped movement space. This ensures, on the one hand, that self-centering of the molding projections in the basic body is provided during vacuum forming. On the other hand, the maximum pivoting mobility of the mold projections by the size of the Angle between the contact surface and the support surface are determined and limited.

The mold projections preferably have outside the guide in the main body to the geometry of the undercut adapted freeforms. This protruding nose relative to the main body to form the undercut on the support plate may be formed in the geometry of the aesthetic requirements and / or the function of the undercut for receiving hoses, pipes or the like, to form Verhakungseffekten with other materials or components.

According to a further preferred embodiment of the invention, it is provided that two adjacent to each other and adjacent, extending in Entformungsrichtung guide surfaces of two adjacent guides on the main body form a column on the end face of the end plate of the hold-down device abuts in a working position. As a result, a defined contact surface can be created, which determines the working position of the mold protrusions. At the same time this allows a simple adjustment of the hold-down force for the hold-down element allows.

The mold projections preferably have their nose-facing engagement surfaces which extend below the end plate of the hold-down device in a working position and a removal position. As a result, it is ensured in both end positions and in the intermediate transition regions that the mold projections are held in the guides. In addition, this can be given a secure hold down the mold protrusions in a working position.

In the transition region between the base body and the base plate, a plurality of small through-holes are preferably formed. As a result, a deformation of the supplied carrier plate is supported to form elevations with undercuts.

It is preferably provided that the through hole is formed in the base plate as a guide for the shaft of the hold-down device. As a result, a simple demolding can be achieved.

According to another preferred embodiment of the invention, it is provided that an elastic element, preferably a foam, is provided at least in sections in the shank of the hold-down device. As a result, targeted guidance of the mold projections during transfer from a working position into a demoulding position can be made possible. In addition, the return of the mold protrusions can be supported in a working position.

Figur 1

eine schematische Schnittdarstellung eines Formzapfens der erfindungsgemäßen Vorrichtung unmittelbar nach dem Vakuumformen einer Trägerplatte,

Figur 2

eine schematische Schnittdarstellung eines Grundkörpers von einem Formzapfen der erfindungsgemäßen Vorrichtung,

Figur 3

eine schematische Ansicht von oben auf den Grundkörper, der auf der Basisplatte angeordnet ist,

Figur 4

eine schematische Ansicht von oben auf einen Formzapfen der erfindungsgemäßen Vorrichtung und

Figur 5

eine schematische Schnittdarstellung der erfindungsgemäßen Vorrichtung gemäß Figur 1 während eines Entformungsvorganges.

The invention and further advantageous embodiments and developments thereof are described in more detail below with reference to the examples shown in the drawings and explained. The features to be taken from the description and the drawings can be applied individually according to the invention individually or in combination in any combination. Show it:

FIG. 1

a schematic sectional view of a forming pin of the device according to the invention immediately after the vacuum forming a carrier plate,

FIG. 2

a schematic sectional view of a base body of a molded pin of the device according to the invention,

FIG. 3

a schematic view from above of the base body, which is arranged on the base plate,

FIG. 4

a schematic view from above of a forming pin of the device according to the invention and

FIG. 5

a schematic sectional view of the device according to the invention according to Figure 1 during a Entformungsvorganges.

Figure 1 shows a partial view in full cross section of a device 11 according to the invention for vacuum forming a carrier plate 12 made of a plastic film. This device 11 comprises a base plate 14, from which a molding pin 16 rises to form elevations 18 with undercuts 19 in the support plate 12 during vacuum forming or deep drawing, wherein the elevations 18 protrude with respect to a support plane 21 of the support plate 12. Such a carrier plate 12 usually comprises a plurality of elevations 18, which are usually arranged in a grid.

The molded pin 16 comprises a base body 25 which is integrally connected to the base plate 14 according to the embodiment. Alternatively, this base body 25 may also be fastened by a detachable connection, such as a screw connection, from a lower side 26 of the base plate 14 and also the upper side thereof. The main body 25 receives in guides 28 form projections 29, which are provided to form the undercuts 19 in the elevations 18. About a hold-down device 31, the mold projections 29 are positioned in a working position 23 as shown in FIG. The hold-down device 31 comprises an end plate 35 which at least partially overlaps the mold projections 29 and a shank 36 which acts on the end plate 35 and extends completely through the main body 35 and the base plate 14 to the underside 26. At a protruding from the bottom 26 end of the shaft 36, a mounting portion 38 is provided, on which a hold-down element 39 engages and is supported on the underside 26 of the base plate 14. This hold-down element 39 is preferably designed as a compression spring. Furthermore, elastically deformable elements can be provided, which can bring about a restoring force as well as a stroke, so that the hold-down device 31 returns automatically to a starting position and holds the mold projections 29 in the working position 33. Alternatively, instead of the hold-down element 39 in the form of a spring-elastic or rubber-elastic element, a mechanical drive may also be provided which drives the hold-down device 31 in a movable manner.

FIG. 2 schematically shows, in solid cross section, a base body 25 provided on the base plate 14. In this embodiment, four guides 28 are provided for receiving in each case a mold projection 29, which are each offset by 90 ° in the base body 25 are arranged. This is just an example. Depending on the application, only one or any number of guides 29 may be provided in the base body 25 and / or the angular arrangement may be different from one another, wherein in principle the same structure for receiving the molding projections 29 is provided in the respective guide 28.

The guide 28 comprises a bearing surface 41 on which a support surface 42 of the molding projection 29 rests in a working position 33. This support surface 41 is inclined to the longitudinal central axis 43 of the base body 25, so that the mold projections 29, which are loosely inserted into the guides 28, can slide independently on the support surface 41 in the direction of the longitudinal central axis 43. Adjacent to the support surface 41 are lateral and in the direction of removal oriented guide surfaces 46 are provided which guide the mold projections 29 so that they are provided within the guide 28 exclusively up and down movable and / or pivotally. The guide surfaces 46 of two adjacent guides 28 adjoin one another and form a column 49 with a portion 47 of a lateral surface 48 of the base body 25. On an upper side of the column 49, an end face 51 is formed, on which the end plate 35 of the hold-down device 31 in a working position 33 the mold projections 29 rests. As a result, a defined position of the hold-down device 31 is ensured in a working position 33 of the molding projections 29.

The support surface 41 of the guide 28 advantageously has a bell-shaped geometry at its free upwardly projecting end. This additional surface serves to support the mold projections 29 in a working position 33 during the vacuum forming of the carrier plate 12 made of a plastic film. The bearing surface 41 extends in the direction of the longitudinal central axis 43 substantially close to or to the bore 53, in which the shaft 36 of the hold-down device 31 is guided longitudinally displaceable.

FIG. 3 shows a plan view of the main body 25 according to FIG. In this plan view, a section of a base plate 14 is shown, which shows that the mold pins 16 are arranged in a grid pattern to each other. In this case, the measures provided for in the guides 28 form protrusions 29, as shown in the embodiment, be arranged along a diagonal of a grid. Alternatively, the molding projections 29 may also be aligned along the grid lines.

For example, in one-piece embodiment of the base body 25 with the base plate 14 transition areas 56 are provided which form a transition with a radius. Passage channels 57 are preferably provided in this transition region 56, which enable the generation of a vacuum directly in the area of the lateral surface 48 of the trunnion 16.

FIG. 4 shows a plan view of a shaped journal 16, in which the main body 25 is completed with the molding projections 29 and the hold-down device 31. The end plate 35 partially overlaps the end face 51 of the pillar 49 as well as the engagement surfaces 61 of the mold protrusions 29.

The mold projections 29 have, as shown in Figure 1 in a side view, a wedge-shaped body. A support surface 42 is opposite to a contact surface 63 at an angle which is smaller than an angle formed between the bearing surface 41 of the guide 28 and the shaft 36. The shank 36 of the hold-down device 31 limits the guide 28 to the longitudinal central axis 43. As a result, a movement space formed within the base body 25 is formed, which is bounded by the support surface 41 and the guide surfaces 46 and by the shaft 36 and the end plate 35. Between the engagement surface 61 and the support surface 42 of the mold projection 29 is provided with a radius transition region 65, so that the loose inserted into the guide 28 forming projection 29 pivotally and / or displaceable, whereby the demolding, as described below in Figure 5, is supported. The engagement surface 61 of the molding projection is formed in parallel, for example, in the area overlapped by the face plate 35. Preferably, the engagement surface 61 is formed as a plane, so that a slight sliding of the engagement surface 61 along one of these associated edge of the face plate 35 is made possible. The mold projections 29 have from the main body 35 outstanding lugs 67, which are formed and shaped according to the desired geometry of the undercut.

The mold projections 29 may preferably be formed of plastic as an injection molded part. Alternatively, metal mold projections can also be used.

In FIG. 5, the device 11 is shown during a demolding phase during lifting in the removal direction of a support plate 12 formed with elevations 18. For removal of the support plate 12, this is withdrawn upward, wherein the mold projections 29 are moved by the inner lateral surfaces of the elevations 18 on the longitudinal center axis 43. In this case, these mold projections 29 mainly perform a pivoting movement and are moved toward the shaft 36. At the same time, the shaft 36 is moved upwardly by the engagement surfaces 61 of the mold projections 29, the end plate 35 shift upward. This movement takes place with increasing restoring force of the hold-down element 39, wherein the hold-down element or elements 39 are designed such that an easy demolding of the vacuum-formed carrier plate 12 is made possible and at the same time it is ensured during the vacuum forming that the mold projections 29 remain in their working position 33.

The hold-down device 31 can furthermore comprise an elastically yielding element which is provided on the shaft 36, in particular near the end plate 35. As a result, a damped movement of the mold protrusions 29 both during the transfer from the working position 33 in a demolding 71 and vice versa. This elastic element may be provided as a foam element or the like.

The device according to the invention can be used both for vacuum forming and deep drawing of a carrier plate 12 made of a plastic film, which have elevations 18 relative to a support plane 21, which are provided with undercuts 19. Such support plates 12 may be provided, for example, as a component for receiving hose or pipes in a floor, wall or ceiling structure. The pipes for the underfloor heating are kept down. Furthermore, this device can be provided for the use of carrier plates as Entkoppelungsmatte between a screed and a floor covering or a wall covering or a concrete floor and screed in the interior or exterior. This device 11 allows the processing of different thicknesses and materials of plastic films or plate-shaped plastics for the production of a carrier plate as well as different sized bumps, which includes any number of undercuts.

All of the above-described features are essential to the invention in each case and can be combined with one another as desired.

Claims (17)

Device for vacuum-forming a carrier plate (12) made of a plastic film with elevations (18) projecting from a support plane (21) and having at least one undercut (19), with a base plate (14) having at least one shaping pin (16) a base projection (25) connected to the base plate (14) and at least one molding projection (29) movably received in the base body (25), the at least one molding projection (29) being in a working position (33) opposite an outer jacket surface (29). 48) of the main body (25) protrudes outward, characterized in that the at least one mold projection (29) is loosely inserted in its guide (28) of the base body (25) and that a hold-down device (31) the at least one in his leadership (28) inserted molding projection (29) between a working position (33) and a demolding position (71) in the guide (28) positioned. Apparatus according to claim 1, characterized in that the hold-down device (31) has an end plate (35) which engages over the at least one shaping projection (29) and is provided on a in the main body (25) extending shank (36). Apparatus according to claim 1 or 2, characterized in that the hold-down device (31) comprises a the end plate (35) having shank (36) which passes completely through the base body (25) and the base plate (14) and at its free end at least one Hold-down element (39) attacks. Apparatus according to claim 3, characterized in that the hold-down element (39) is a spring element, preferably a pressure-resistant spring element. Device according to one of the preceding claims, characterized in that a shaft (36) of the hold-down device (31) limits the guide (28) of each mold projection (29) to the longitudinal central axis (43) of the shaped journal (16). Device according to one of the preceding claims, characterized in that the guide (28) of the mold projection (29) in the base body (25) has a bearing surface (41) which protrudes from a nose (67) of the molding projection (67) projecting beyond the base body (25). 29) in the direction of the longitudinal center axis (43) of the shaping pin (16) to the base plate (14) is inclined sloping. Apparatus according to claim 6, characterized in that a support surface (42) of the mold projection (29) in a working position (33) on the support surface (41) is supported. Device according to one of the preceding claims, characterized in that the guide (28) of the mold projection (29) in the removal direction aligned and arranged parallel to each other guide surfaces (46), within the mold projection (29) slidably and / or pivotally to the guide surfaces ( 46) is guided. Device according to one of the preceding claims, characterized in that the mold projection (29) to the inner end of the guide (28) facing, which between the support portion (41) of the guide (28) and the shank (36) of the hold-down device (31) is, a rounded transition region (65) which connects the support surface (42) with an opposite contact surface (63) of the shaping projection (29). Device according to one of the preceding claims, characterized in that between a bearing surface (41) of the guide (28) and a shank (36) of the hold-down device (31) a wedge-shaped movement space for the mold projection (29) is formed, the contact surface (63) and support surface (42) are arranged at an angle to each other, which is smaller than the angle between the wedge-shaped movement space forming elements. Device according to one of the preceding claims, characterized in that the at least one shaping projection (29) outside the guide (28) in the base body (25) to the geometry of the undercut (19) adapted freeforms. Device according to one of the preceding claims, characterized in that between two in the removal direction extending guide surfaces (46) of two mutually adjacent guides (28) adjacent to each other, a column (49) is formed, on whose end face (51) the end plate ( 35) of the hold-down device (31) in a working position (33). Device according to one of the preceding claims, characterized in that the at least one shaping projection (29) has an engagement surface (61) pointing in the direction of the freestanding lug (67), which extends below the end plate (35) of the hold-down device (31) in one Working position (33) and a demolding position (71) extends. Device according to one of the preceding claims, characterized in that in a working position of the at least one mold projection (29), the engagement surface (61) of the mold projection (29) for engagement with the underside of the end plate (36) of the hold-down device (31) is formed and preferably running parallel in the same plane as the end face (51) of the column (49) is aligned. Device according to one of the preceding claims, characterized in that in a transition region (56) between the base body (25) and the base plate (14) a plurality of the base plate (14) passing through passageways (57) are provided. Device according to one of the preceding claims, characterized in that a bore (43) in the base plate (14) as a guide of the shank (36) of the hold-down device (31) is formed. Device according to one of the preceding claims, characterized in that on the shank (36) of the hold-down device (31) at least in sections an elastic element, preferably a foam, is provided.

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